larryfoster wrote:At a certain point, I have to decide if I want to throw more money at it

Larry, I'm sure this machine has sentimental value or you wouldn't be trying to keep it going. The truth is, it isn't like the old Cubs where parts are still abundant. Once you have the carb fixed it may well be that something else goes. By time you get done you will have more in it than a new one and still have a 30 year old trimmer that could go at any time.

If it were me there would be a new one in the shed in the morning. Now, like I said, if it were me. I'm just throwing that out there for thought.

It is common sense to take a method and try it. If it fails, admit it frankly and try another. But above all, try something.- Franklin D. Roosevelt -

Appreciate your thoughts, Barnyard.Youre right about sentiment.Betsy has sentimental and utilitarian value. I can tell stories about Betsy 1 when I was a kid and Betsy 2 was also my dad's and a path towards both my roots and a chance at improving my self reliance

The trimmer is just a darn good machine and they don't make 'em like that anymore.If I can't get it to run, I'll just have a little more brush or weeds around the edges.

I have a feeling that the problem has a simple cause. But, I am simpler than the problemA cheap little fuel filter may do it.Ethanol may be the cause of the fuel filter failure. Maybe not replacing the gasket when I replaced either carbThose are cheap fixes and worth monkeying with.And I do get a little anal when I try to solve something.You may have noticed that in this thread

Ethanol is a huge factor here. These were never designed to run on ethanol so you it would be best is you can find some decent gas or get a few more spares cause the ethanol will affect the gaskets and such. Thankfully there are some gasket sets available. I am pretty comfortable now to say that you are looking simply at fuel starvation. The last link I posted showed the fuel line and filter for less than $11.00. That would solve the problem. The other issue is the gasket, you have to have that or you are sucking in too much air. I don't think RTV or silicone is a good idea here, best to use what Stihl recommended and that is the gasket.

Yes there is a point at which things become too expensive to fix unless there is a personal reason why you want to keep it. I happen to like my brush saw ... it is a professional and I simply cannot nor do I want to spend the kind of money I need to if I am going to replace it. I had my saw checked and my big problem is the engine/carb end. The rest is in top notch shape and should be good for another 10 or 15 years. I don't use mine every day and I take it neither do you, so it makes sense to try and fix it. However throwing money at it is not the best solution. I think you probably have enough in it by now to be able to say that it is fuel starvation. Get that solved and you should have this thing running nicely.

Hopefully this will be the final piece to the puzzle. Also here is another point, it is a great project to learn on. I have been after my father-in-laws 1976 Mercury 440 T.T - and it is now mine. PowerPak is shot - big problem will be to find the powerpak - they are no longer made ... thankfully there is one guy up in Kirkland Lake that bought up most of Mercury's stock pile before they shut it down. So I might be able to get the powerpak. If not, then it is a simple re-engine job. Reason I want it is that the very 1st sled I owned was a '76 440 T/T which I had at CFS Inuvik. Dad and I did a lot of riding on his two T/T's in the late 80's and 90's. They pretty much have sat since then and the other 440 and the 340 are now gone so this one is special to me which makes it worth rebuilding/re-engining if needed. .

Some additional info that may benefit someone other than me.I was able to talk to a real nice guy who was a Stihl dealer for 26 years.He suggested checking the flange that the carb mounts on for cracks

On Ebay, his seller id is r-e_power-equipment.

He offered to walk me through all of this.Between him and all the generous patient help I have gotten here, I bet I can get it running like a new one.

Eugene wrote:Have you taken the weed eater to a dealership with factory trained employees, that only works on Stihl products?

I never saw you respond to Eugene's question. His was probably the best advice you can get. Rudi has really been working to try to find a solution for you and I have been doing a lot of internet research on this that has taken me to many different websites. You obviously have had this problem for quite some time with suggestions from several different people and nothing positive is getting done. If you are so intent on keeping this machine you need to put this to rest and get it to someone who works on Stihl equipment.

L. Arnold & Sons Hardware in Natrona Heights and Powerup Equipment Inc in Butler have factory certified service technicians. Those would be the people who know how to get it running agin. Both dealers are within 25 miles of you. I suggest you contact one of these folks and let them tell you exactly what is wrong.

That seems to be the only recourse left. At this point, trying to fix it over the internet will not get it running.

It is common sense to take a method and try it. If it fails, admit it frankly and try another. But above all, try something.- Franklin D. Roosevelt -

I have had it to several repair shops.Thought I mentioned this somewhere above but it could be my senile, ADHD blondness

The one most local to me has been closed for a while and they had been pretty worthless since the original owner sold it to the last group.

I, most recently, had it to a stihl dealer another town away.They tried to rebuild the original carb and told me it was shot.I fiound the used carb and when I failed, took it back to them. It was there for weeks.

I don't believe they even looked at it.Good news is they didn't charge me anything.Just a guess is that they didn't sell it so they may not have been anxious to work on it

It is true that the carb staying adjusted problem has been going on for a while.The first guy, several years ago, wasn't a Stihl dealer; just a small engine guy.He had it so it would run for a while.Of course, he removed the primer assembly for some reason, and my muffler which always worked loose even when new..I do appreciate all the patient help that has been given here.

Kinda hard to repair something when it has been "altered" a number of times by several different individuals.

Yes, the new heavier duty weed eaters, brush cutters, are expensive. This summer, finally gave up on my son in-laws 20 plus year old Stihl weed eater and just purchased him a new one. The new Stihl should last him another 20 or so years.

Anyway. Have you ask the Stihl dealers if they have any FS80's or equivalent machines in their junk pile. Local Stihl dealers usually have a pile of machines at this time of year. Kinda surprised that a Stihl dealer can't get the FS80 back into shape. Local dealers have a large number of old machines on the shelf that they part out.

My newest local guy is courteous but not terribly responsive.I'm sure he is more interested in selling me a machine than fixing one he didn't sell.

I'm on the lookout for a fuel assembly and I can get a bulb.After I check the flange for possible cracks, my newfound friend from Ebay may have what I needIt got cold so I haven't been doing a lot of that kind of work for a couple days

I try not to consider a lot of Ebay sellers as friends. They don't know me and most Ebayers are only there for the money. They are friendly as long as they can get into your wallet.

If you are having a problem with a Stihl authorized dealer contact Stihl directly. They want to know these things. That is why the dealer is authorized. Stihl does not let just anybody say they are a stihl dealer. If the guy you are taking it to is not a Stihl mechanic you may well have more problems. As Eugene stated, Stihl mechanics have been known to stash spare parts.

It is common sense to take a method and try it. If it fails, admit it frankly and try another. But above all, try something.- Franklin D. Roosevelt -

I appreciate your input on this, Barnyard.All advice I have gotten here has always been spot on and given in the spirit of genuine helpfulness.As you may have noticed, I can be rather bone-headed.

It's not my style to tattle on someone.I vote with my $$$.

I use the term "friend" somewhat loosely when referring to the Ebay guy.He's already gotten the money for the biggest ticket item, the carb.

I agree that Ebay sellers tend to be only interested in the sale. In fairness to this guy, he offered the help and right now he's only looking to sell me a couple gaskets.In the end, probably more, though.But, not a lot more

Barnyard wrote:If you are having a problem with a Stihl authorized dealer contact Stihl directly. They want to know these things. That is why the dealer is authorized. Stihl does not let just anybody say they are a Stihl dealer. If the guy you are taking it to is not a Stihl mechanic you may well have more problems. As Eugene stated, Stihl mechanics have been known to stash spare parts.

Larry:

Bill has given you some real good advise. Stihl is very particular with their dealers and they want to know if any are under-performing or discourteous. Service is the hallmark of German business (lived there, grew up with it, practice it) and discourteous or lazy dealers will soon be former dealers.

I have a standing watch with Roger for any FS 80's, AV's or AVR's as parts machines. I intend to keep my 80 running as long as possible. I like it that much. Sometimes I can be kinda anal as well, it is a Bavarian trait - it is in the gene's This probably explains my obsession with Cubs